This is the final phase of an adult follow-up study of boys with Hyperkinetic/Attention Deficit Disorder (HK/ADD), of their nonhyperkinetic full brothers, and of their nonhyperkinetic former classmates. All patients were originally referred at ages 4 to 12 to the University of Iowa child psychiatry outpatient clinic. The samples include: a) an Early Medicated group (referred between 1967-1972 and methylphenidate); b) a Transitional Medicated group (referred between 1972-1975 and treated primarily with methylphenidate); c) a Transitional Unmedicated group (also referred between 1972-1975,ut, because of physician preference, not treated with psychotropic drugs); and d) a Late Unmedicated group (referred between 1976-1978 and not treated with psychotropic drugs). The general aim of these studies is to (a) describe the adult outcomes of HK/ADD and compare them with the outcome of biological brothers and classmate controls; and (b) to identify those subject and environmental characteristics that predict differences in outcome. Planned comparisons will test the effects on outcome of such variables as hyperactivity and aggression; stimulant drug treatment; response to medication; and substance use/abuse. Establishing methods for predicting and diagnosing residual ADD/adult MBD will be a special concern. In 1988 and 1989, the 21-to-23-year-old follow-up of 155 Early Medicated probands and 66 brothers was completed. In addition, the majority of the Transitional and Late groups (72 probands, 24 brothers, and 51 classmates) also completed their evaluations at ages 21 to 23. Finally, 71 probands in the Early Medicated group an 31 of their brothers were evaluated at ages 28 to 32. In the proposed two-year grant period, data analysis for the 21 to 23 year old samples will be conducted. Analyses that are appropriate for the partial sample of 28 to 32 year old subjects and brothers will also be conducted.